I mean... Maybe I am just oversimplifying things or misreading something, but if the cabinet the switch was on was metal then maybe the switch connected ground to ground? Suddenly changing ground to ground can crash old hardware quite reliably but booting with another ground plate could make it adjust the potentials properly... I've done this multiple times in a lab, in essence adding more ground causes the ground plates to equal out and that sudden drop can crash sensitive hardware...

Please tell me i am wrong I want this magic switch to be true so bad